Objective: To define the demographic risk profile and stage at diagnosis among the head and neck cancer (HNC) patients reported in two hospital-based cancer registries in Andhra Pradesh. Materials and Methods: A cross-sectional study was conducted in patients with histologically confirmed diagnosis of squamous cell carcinoma of the head and neck during 2002-2006. Data on the demographic profile and clinical information were obtained from hospital and clinical records. Staging was based on the American Joint Committee on Cancer and included primary tumor size (T), regional neck status (N), and group stage. The site of cancer was classified based on the International Classification of Disease for oncology (ICD-02). Results: A total of 5458 cases of HNC were included in this study. Majority of the subjects were in the age range of 40-69 years with a significant male preponderance in all the age groups (P<0.001). The most common habit was the combination of smoking, alcohol, and chewing in both males and females (20.1 and 35.1%, respectively) (P<0.001). Tongue and buccal mucosa were the most common sites of cancer in both males (26.8 and 12.8%, respectively) and females (22.9 and 19.8%, respectively) (P<0.001). Tongue was the commonest site of cancer occurrence with respect to all the habits (both singly and in combination) except for chewing tobacco where buccal mucosa was the most common site. Males were more likely to be diagnosed in stage 3 (37.6%) and 4 (20.6%), while females were diagnosed in stage 1 (36.3%) and 2 (32.7%) (P<0.001). Conclusion: A male preponderance of cancer occurrence and combination of all the three habits (smoking, alcohol, and chewing) were found to be the significant risk factors. Males were more likely to be diagnosed later than females.

Head and neck cancers (HNCs) are the sixth most common malignancy and are a major cause of cancer morbidity and mortality worldwide. In India and South East Asia, oral cancer incidence accounts for up to 40% of all the malignancies. [1] The overall survival percentage has not changed in recent years in spite of extensive research on the biological and molecular aspects of cancer. [2]

The most common risk factors associated with HNC are tobacco and alcohol use with significant interaction observed between the two. [3] Other reported risk factors in the existing literature are poor oral hygiene [4] and the human papillomavirus (HPV) 16 for tongue, tonsil, and oropharyngeal HNC and in non-smoking cases of HNC. [5] In South Asian countries, the risk of HNC is further aggravated by smoking of bidis, [6] reverse smoking, and chewing tobacco, betel quid, and areca nut. [7]

The prevalence of cancer is often strikingly dissimilar in different groups of population, varies greatly from one community to another, and differs in different communities in the same geographic location, depending on the practices and lifestyles of the people in that location. Moreover, differences have been observed in the etiological, clinicopathological, and molecular pathological profile in the tobacco smoking, chewing, and alcohol associated oral cancers, particularly in the Indian subcontinent.

To identify and quantify the etiological profile that might be implicated in a selected population, it is essential to determine the behavioral patterns, habits, customs, and environmental background of the group under study. It is necessary to identify the differences, if any, in the sites, patterns, and incidence rates of the disease amongst various communities living in geographic areas having varying patterns of climate and physical environments by identifying dietary habits, social customs, and such other factors. Many independent researchers [8],[9],[10],[11],[12] had reported the wide ranged prevalence of oral cancer and its risk factors in various parts of the country, but there is a scant literature concerning the risk factor profile of oral cancer patients in Andhra Pradesh. Since considerable differences exist in the consumption of tobacco, alcohol, diet, literacy, social status, and availability of the services in the state of Andhra Pradesh compared to the other states, we attempt to define the demographic, risk profile, and stage at diagnosis among the group of HNC patients reported in two hospital-based cancer registries in Andhra Pradesh during the period of 2002-2006.

» Materials and Methods

Patients' selection, data collection, and variables

The study population consisted of 5621subjects (males: 3742 and females: 1879) out of which 5458 (males: 3653 and females: 1805) were new patients with a histologically confirmed diagnosis of squamous cell carcinoma of the head and neck, who reported during the period from 2002 through 2006 in two hospital-based cancer registries of Mehdi Nawaj Jung (MNJ) Institute of Oncology and Regional Cancer Center, Hyderabad, and Indo American Cancer Institute and Research Hospital, Hyderabad, Andhra Pradesh, India. The demographic profile and clinical information obtained includes the information on age, gender, site of origin, risk factor, and stage at presentation. However, subjects without the risk factor information were excluded (n = 163; males = 89 and females = 74). Staging was based on the American Joint Committee on Cancer and included primary tumor size (T), regional neck status (N), and group stage. [13] The site of cancer was classified (C32.0-32.9) based on the second edition of the International Classification of Disease for oncology [14] (ICD-02), depending on the 11 presentation sites of HNC: base of tongue (BOT), tongue, buccal mucosa, palate, floor of mouth (FOM), lip, gingiva, oral cavity, oropharynx, nasopharynx, and hypopharynx. This study was approved by the MNJ cancer hospital Ethical Committee.

Statistical analysis

The data were analyzed using SPSS version 14 (SPSS Inc., Chicago, IL, USA). Chi-square test was performed to assess the association of gender with age groups, habits, site, and stage of cancer. The risk factor associations were reviewed and compared with site and habits. P value of <0.05 was considered to be statistically significant.

» Results

A total of 5458 cases of oral cancer were reported during the study period. In all the age groups, there was a significant male preponderance (P< 0.001). Among both males and females, the highest incidence of oral cancer was seen within the age group of 40-69 [Table 1].

One-third of females (32.9%) and one-sixth of males (15.4%) were free of risk factor habits. The most common habit was the combination of smoking, alcohol, and chewing, both in males (20.1%) and females (35.1%). This was followed by smoking (17.9%) and alcohol consumption (13.7%) among males and chewing only (16.3%) in females [Table 2].

The most common sites of cancer in both males and females were tongue (26.6 and 22.9%, respectively) and buccal mucosa (12.8 and 19.8%, respectively). This was followed by rest of the oral cavity (12.1 and 14.9%, respectively), hypopharynx (12 and 11.2%, respectively), oropharynx (9.8 and 8.8%, respectively), and nasopharynx (9.3 and 9.4%, respectively). The least common sites were gingiva, lip, and base of the tongue in both the genders [Table 3].

Subjects with smoking/alcohol/smoking + alcohol together had an influence of cancer more commonly in tongue (33.5, 36.8, and 28.5%, respectively) followed by rest of the oral cavity (16.6, 12.4, and 18.5% respectively) and buccal mucosa (10.7, 11.8, and 17.4% respectively). Buccal mucosa (21.4 and 30.2%) was the commonest site for subjects with chewing tobacco and alcohol + chewing habits, followed by tongue (19.4 and 23.4%) and rest of the oral cavity (12.9 and 7.8%). Subjects with a combined smoking and chewing habit had cancer more likely in tongue (24.4%), followed by buccal mucosa (18.9%) and palate (15.3%). Among the subjects with all the three habits, the common site of cancer was the tongue (29.5%), followed by buccal mucosa (18.2%), rest of the oral cavity (13.7%), and hypopharynx (13.6%). Subjects without any habits had cancer in nasopharynx (21.2%), tongue (15.7%), oropharynx (15%), and hypopharynx (14%) more commonly than rest of the sites. Overall, tongue was the commonest site of cancer occurrence with respect to all the habits (both single and in combined) except for chewing tobacco where buccal mucosa was the most common site [Table 4].

The distribution of male patients in relation to stage at diagnosis was in the order of 17.5, 24.3, 37.6 and 20.6%, while among the female patients it was 36.3, 32.7, 24.6 and 6.4% for stages 1, 2, 3, and 4, respectively. Overall, a significantly higher number of males were diagnosed in stage 3 and 4, while females were diagnosed in stage 1and 2 (P<0.001) [Table 5].

The present study was a retrospective and hospital-based study which focused only on the histologically confirmed cases of HNC patients. A male preponderance of cancer occurrence in the present study population suggests that males most often indulged in the habits that are risk factors for HNC, i.e. smoking (particularly bidi, a country cigarette), chewing (may be tobacco and gutkha), alcohol (locally made liquor called toddy), and a combination of these, than the females. Also, higher incidence of males with cancer and later incidence of cancer in the study population than the females may be due to the longer duration of customized risk factor habits, diet, and occupation. Also, men do not get diagnosed until their malignancy reaches an advanced stage. Further, smoking affects primarily in the late stage in the process of oral cancer which is more frequent among males than females. The reported sex difference is attributed to heavier indulgence in the risk habits by men and exposure to sunlight (lip cancer) as a part of outdoor occupations.

The most common habit in both males and females was the combination of all the three habits (smoking, alcohol, and chewing tobacco). In the present study population, alcohol consumption seemed to be surprisingly high. This can only be explained possibly because culturally toddy is considered to be as a socially accepted drink in Telangana region of Andhra Pradesh. Women drink toddy to be relieved of body aches, have good sleep at night, and make them prepared to work on the next day. [15] The hospitals chosen were the nearest cancer referral centers in this particular region and the culturally accepted toddy drinking habit in females might be one of the risk factors for cancer occurrence. [16] Following the combined risk factors like smoking, chewing, and alcohol habits, chewing habit and smoking were the most common habits in females and males, respectively, because females in our society are not indulged in tobacco smoking but likely to inculcate chewing habits. Similarly, in the current study, buccal mucosa was the common site in females than in males probably due to the dominant chewing habit and the prolonged contact of the mucosa to the quid. [17]

Tongue and buccal mucosa were the most common sites of cancer among males and females. This was similar to the reports of Iype et al., [9] and Mehrotra et al., [10] and Kuriakose et al., [17] where it was also highlighted that in older patients, cancer of tongue was always associated with smoking, alcohol, or chewing. A constant contact with the quid while chewing can be one of the reasons for higher prevalence of cancer in buccal mucosa and tongue. A significant number of patients had reported that they had no habit history. Unfortunately, using registry data, we have inadequate information on other risk factors (HPV-related cases of HNC), which possibly could indicate the frequency of non-habit related cases of HNC.

Although the current study was a hospital-based one, it highlights the risk factor profile of cancer patients from state of Andhra Pradesh. The data reflect a specific patient population but not the community as whole. Though the results from the study cannot be extrapolated directly to the general population, the data help in understanding the possible risk factors and behavior patterns in HNC patients. Cultural differences in the use of tobacco and toddy drinking habits lead to a variation in the geographic and anatomic incidence of HNCs among these patients. More than half of the study population had indulged in smoking, highlighting the need for prevention through common risk factor approach. Tobacco with or without other risk factors has been shown to be related to many multi-system disorders. Hence, there is an urgent need for taking appropriate prevention strategies through common risk factor approach along with intense educational program to revert back the present scenario of such preventable diseases.

The lack of proper standardized recording format to quantify the risk factors was also one of the drawbacks of our study. Cancer registries should design and use standardized format for recording the habits like tobacco and alcohol, their duration, and frequency, along with other risk factors such as oral hygiene, nutrition, viral infections, educational and socioeconomic status. The use of established classification like that of ICD-10 for cancer coding allows comparison with the other populations. Hence, further studies using such standardized format for recording habits are needed to understand the geographic, anatomic, histological, and cultural variations in the prevalence of HNC among the populations.